This invention will be particularly discussed in relation to stent grafts for placement into the thoracoabdominal aorta for the treatment of aneurysms and more specifically in relation to juxtarenal placement. The invention, however, is not so restricted and may be applied to stent grafts for placement in any lumen of the human or animal body.
There has been devised a thoracoabdominal stent-graft with one or more side arms for the celiac, superior mesenteric and/or renal arteries. One particular form of stent graft includes a side arm which is a graft material tube which extends at least partially helically around the stent graft from a fenestration or ostium in the stent graft. Such a graft material tube can be formed from a corrugated graft material.
U.S. Pat. No. 7,105,020 entitled “Branched Vessel Endoluminal Device” describes various forms of helically extending side arm stent grafts and the teaching therein is incorporated herein in its entirety.
These helically extending side arm stent grafts may include radiopaque markers along the length of the helical branch to assist a physician with correct placement by radiographic techniques of the helically extending side arm stent graft into the aorta of a patient with the open end of the side arm directed towards a branch vessel of the aorta. The stent graft is constricted into an introduction device under a delivery sheath for introduction into a patient using endovascular techniques and during assembly onto the introduction device the side arm can be distorted out of its helical position. This can make the correct radiographic visualization of the position of the open end very difficult during the introduction procedure.
It is the object of this invention to provide an arrangement by which the side arm is constrained during assembly so that it remains in a desired position for introduction.
Although the invention will be generally discussed in relation to side arms for stent grafts which extend helically around a stent graft body the invention is not so restricted and may also be applied to other forms of side arm.
Throughout this specification the term distal with respect to a portion of the aorta, a deployment device or a prosthesis means the end of the aorta, deployment device or prosthesis further away in the direction of blood flow away from the heart and the term proximal means the portion of the aorta, deployment device or end of the prosthesis nearer to the heart. When applied to other vessels similar terms such as caudal and cranial should be understood.